
It is already demonstrated in
[1]} that the constraint \(\Theta =0\)  implies
the appearance of a cavity around the center (\(r=0\) ) of matter
configuration . Let us consider the constraint \(\mathbb {U}\ne 0\)  and
\(D_{T}(\delta l)=0\) , which corresponds to solely areal evolution.
However, the condition \(D_{T}(\delta l)=0\)  implies \(B=B(r)\)  and the
re-parametrization of \(r\)  enables us to consider \(B=1\)  providing
\(C^{\prime }=\mathbb {E}\) . Then, utilizing Eqs.(REF ) and (REF ), we
get
\(\frac{\Theta }{2}=\frac{\mathbb {U}}{C}=-\sigma .\) 
